Gluconeogenesis and nitrogen loss after stomach resection

The relationship between gluconeogenesis from alanine and nitrogen balance after stomach resection was investigated in 13 patients. Partial stomach resection was done in eight patients and total stomach resection was done in five patients. Alanine turnover, carbon flux from alanine to glucose, and glucose turnover were determined by tracer methodology, using the single injection of [U-14C]alanine and [2-3H]glucose. The patients were divided in two groups according to the quantity of administered glucose. Six patients with partial stomach resection received 2.1 to 2.8 g glucose . kg-1 . day-1 and 0.07 to 0.09 g nitrogen . kg-1 . day-1, amounting to 11 to 13 kcal . kg-1 . day-1 (group 1). In group 2 the subjects received 5.4 to 8.2 g glucose . kg-1 . day-1 and 0.12 to 0.26 g nitrogen . kg-1 . day-1; five patients received also 1.2 to 1.8 g fat emulsion . kg-1 . day-1. Total caloric supply was 28 to 60 kcal . kg-1 . day-1. In group 1 the mean potential contribution of gluconeogenesis from alanine to nitrogen loss was between 31 and 67%; in group 2 this contribution was at least 7 to 63%. No correlation was found between nitrogen balance and carbon flux from alanine to glucose. A significant correlation (p less than 0.001) was found between nitrogen balance and, respectively, nitrogen intake and caloric supply. These results suggest that not gluconeogenesis from alanine but nitrogen and caloric demand are major factors influencing nitrogen balance after stomach resection.